Recently i have had my 40d that i use modified, now it was a 2 fold reason, to use for astronomy and also for IR/UV photography so the mod was just a simple removal of the old filter.
Now im using a Astronomik Screw In UV/IR filter to make it work properly in the astronomical mode. BUT. being a uni student who cannot afford a $400 dollar feathertouch or the like i need to make things work!
So the old SW focuser got a tune up, re grease and it works for all intents and reasons well enough for me. problem... now i use a screw in filter getting focus isn't easy because my old methods of utilizing the exsisting adaptors does not work.
FIX...
the sneaky squirrels made a 2" adaptor, and a 1 1/12" adaptor and the top of the focuser tube has a screw in plate so that both these adaptors can be swapped in and out thing is a 2" barrel will not pass this screw in plate. (this is where my problem lays!) to get a MPCC down far enough it needs to be about 4 mm deeper than this ring will allow.
So simple mod for all you guys who cannot afford the very best
make it work by asking somebody to mill a few hundreths of a mm off. job right, the 2" barrel now passes though this plate and your off to your filters/focus heaven.